Pen tip construction forming secondary ink reservoir

ABSTRACT

An inking pen recording system with inking pens having pen tip inserts with their upper ends shaped to cooperate within mounting chambers to form secondary ink reservoirs. The pen tips may be made of solid or fibrous material.

O United States Patent 1 [111 3,771,166

Tullos Nov. 6, 1973 PEN TIP CONSTRUCTION FORMING [56] References Cited SECONDARY INK RESERVOIR UNITED STATES PATENTS [76] Inventor: Aubrey R. Tullos, P.O. Box 2373, 535,588 3/1895 Horton 401/198 Odessa, Tex, 79760 2,416,596 2/1947 Rosenthal 3,644,933 2/1972 Tullos et a1. 346/140 [22] Filed: July 24, 1972 [21] Appl 274 24 Primary ExaminerJ0seph W. Hartary Attorney-William A. Strauch et a1. Related [1.8. Application Data [63] Continuation-impart of Ser. No. 222,047, Jan. 31, [57] ABSTRACT 1972' An inking pen recording system with inking pens hav- [52] U s 346/140 401/198 ing pen tip'inserts with their upper ends shaped to co- [51] hit Cl G61! 15/16, oper atewithin mounting chambers to form secondary Fie'ld 401/198 ink reservoirs. The pen tips may be made of solid or fibrous material.

7 Claims, 6 Drawing Figures 1 PEN TIP CONSTRUCTION FORMING SECONDARY INK RESERVOIR CROSS REFERENCE TO RELATED PATENTS AND APPLICATIONS This application is a continuation-in-part application of US Pat. application Ser. No. 222,047, filed Jan. 31, 1972 for Inking Pen Constructions. Pen Systems with which the present invention is useful are disclosed in detail in U.S. Pat. No. 3,644,933 issued Feb. 22, 1972 for Reservoir Type Inking Pen System; US Pat. No. 3,653,070 issued Mar. 28, 1972 for Nested Sleeve Recording Pen Head; and my copending US application Ser. No. 243,004 filed Apr. 11, 1972 for Replaceable Pen Tip Mounts.

BACKGROUND OF THE INVENTION This invention relates to capillary feed inking systems used with a wide variety of recorder apparatuses in drawing fine lines on timed or stationary, drum or circular recorder charts. Specific inking systems and pen head structures are disclosed in the aforementioned United States patents and copending US applications.

The inking pen used insuch systems comprises a capillary pen tube, connected to a source of ink by a thin,

flexible capillary tube, a pen tip mounting chamber into which a solid material or fiber pen tip is inserted, and a clip assembly or silver solder means which mounts the pen tube and associated pen tip and mounting chamber onto the recorder arm of a recording apparatus. One or more of the components just described are disclosed in the above identified US Patents and copending application and in the following US. Patents: Nos. 1,179,925; 1,405,409; 1,895,727; 1,917,572; 2,176,777; 2,800,385; 2,800,418; 3,264,652; 3,278,942; 3,361,516; 3,452,359; and 3,510,934. See also French Patent No. 1,243,524.

Dependable flow action and easy replacement of one or more parts of the inking pen assembly are desired features in this field. Dependable flow action is achieved by provision of a secondary ink reservoir immediately above the pen tip. I-Ieretofore, such reservoirs have beenformed entirely within the pen tip mounting chamber, as disclosed in the above mentioned reIated'UQS. Pat. Nos. 3,644,933 and 3,653,070, and in US. Pat. No. 3,653,070, or entirely within the top of the pen tip, as disclosed in my above mentioned copending US application Ser. No. 243,004. The present invention provides such a reservoir formed partially by the pen tip upper end and partially by its mounting chamber, without need of special machining or forming of the chamber. Additionally, the pen tip is friction fitted into its mounting chamber for easy replacement.

SUMMARY OF THE INVENTION inking pen wherein a pen tip is friction fit into a mounting chamber and forms a secondary ink reservoir therewith to assure dependable inkflow through the inking pen.

Yet another object of the invention is to reduce the cost of manufacture of secondary ink reservoir type inking pens by providing structure forming such a reservoir without need of special maching or forming of the pen tip mounting chamber.

Further novel features and other objects of this in- I vention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED- EMBODIMENTS The inking pen system to which the instant invention is directed includes an ink' bottle or container 10 retained on a steel wire hanger 12 by means of an encircling band or clip 14. The bottle 10 may be made of resilient plastic and in cooperation with clip 14 is vertically adjustable along the length of hanger 12 to enable proper ink flow. A bottle stopper 16 supports a vertically disposed capillary stinger 18 which projects downwardly into the bottle 10. A suitable length of fine diameter, extremely flexible plastic tubing 20 transfers ink from bottle 10 to the inking pen 22, and more specifically from stinger 18 to pen tube 24. Preferably, both stinger l8 and pen tube 24 are made of stainless steel capillary tubing of extremely small dimensions (0.0355 O.D. X 0.023 inches I.D.) while plastic tubing 20 is made of Tygon plastic (0.059 O.D. X 0.028

inches I.D.);'in both cases, dimensions are not critical.

Pen tube 24 is bent through an angle of approximately at 26 and terminates in an inking pen head structure which basically comprises a pen tip mounting chamber 28 having a'pen tip 30 insertedor spigotted up into the bottom thereof.

A secondary ink reservoir 32 is provided by shaped upper end 34 of pen tip 30 and the pen tip mounting chamber 28, between end 34 and ink inlet end 36 of pen tip mounting chamber 28. Further details of the pen tip shaped upper end 34 are set forth in detail below.

The portions of the circular chart recorder shown include an operating recorder arm 38 and circular chart 40, which in a conventional installation is rotated by a timed drive and produces a timed recording in conjunction with movement of recorder arm 38 responsive to some condition being recorded.

In a preferred embodiment, recorder arm 38 comprises a flat, thin elongate stainless steel leaf spring extension 42 removably secured to the main body of recorder arm 34 by means of a thumb screw 44 engaging bifurcated end 46 of spring extension 42. A location pin 48 assures lateral stability of the structure.

Controlled lateral positioning of inking pen 22 is provided by adjustment assembly 50 for precise calibration of the recorder apparatus with respect to the chart. Assembly 50 includes a micrometer screw 52 threaded 3 through a post 54 to laterally adjust spring extension 42 and a pivot 56. Further details of this precise structure are adequately set forth in prior U.S. Pat. Nos. 2,752,220 and 3,264,652.

In the embodiments shown, pen tip mounting chamber 28 comprises a single machined element of tubular steel bonded to the lower terminal end of pen tube 24 by silver solder 58, at the ink inlet end 36 of chamber 28. Preferably, pen tip 30 comprises a bundle of stranded materiaLinherently defining a multitude of extremely fine capillary ink passageways oriented vertically from upper end 34 to writing surface contact area 60. The material may be a stranded synthetic material such as nylon, or compressed bamboo fibers. Alternatively, the pen tip may be formed of a solid synthetic material such as nylon (FIG. 3, numeral 30a) and have a hairline capillary ink passageway 62 formed vertically concentrically therewithin. As shown in FIG. 4, a fiber pen tip may also have such a passageway formed therein which in this case will be of greaater diameter than the capillary passageways inherently formed in the fibrous material constituting the pen tip 30.

The function and operational advantages of secondary ink reservoir 32 are set forth in detail in the above mentioned prior US. Pat. Nos. 3,644,933 and 3,653,070. In summary, the ink reservoir provides a secondary, ready supply of ink in a capillary ink flow system which minimizes the possibilities of ink blockage by drying in-the system by providing a supply of liquid ink immediately above and therefore adjacent to the writing pen tip of the inking system.

In the prior US. Pat. Nos. 3,644,933 and 3,653,070, pen tip mounting chambers are disclosed having a machined internal abutment shoulder to limit insertion of the pen tip thereby forming an ink reservoir immediately above the pen tip in the former patent, and similar structure is disclosed in the latter patent except that the pen tip insertion limiting abutment shoulder is formed by a stainless steel sleeve.

Other prior art examples of forming such a reservoir 32 are illustrated in my prior copending application Ser. No. 243,004 and in FIG. 3 of this application whereina cylindrical recess is disclosed in the prior application, while in this application a conical recess 64 is formed or machined at upper end 34 of pen tip 30a to comprise the substantial portion of secondary reservoir 32, the remainder of the reservoir being defined by the upper internal end of pen tip mounting chamber 28. Thus the need for an internal shoulder in chamber 28 to limit insertion of a pen tip in order to form the desired secondary ink reservoir is dispensed with, resulting in a substantial saving over the structure shown in the above mentioned U.S. Pat. Nos. 3,644,933 and 3,653,070.

Similarly in the embodiment shown in FIG. 4, a conical recess 66 is machined or formed in the upper end 34 of a fiber pen tip 30 to provide the substantial portion of desired secondary ink reservoir 32, the remainder of the reservoir being defined by the upper internal portion of mounting chamber 28.

7 However, whether a machining operation is necessary in the chamber 28 or at the upper end 34 of the pen tip, cost of the operation remains high. A significant feature of this invention is a less expensive procedure involving at least one simple external cut such as illustrated in FIGS. 5 and 6 at 68. Thus the angle cut at tip upper end 34 forms a flat planar surface 68 which, together with a substantial portion of the interior surface of mounting chamber 28, forms the desired ink reservoir 32. Because of the angle cut, insertion of pen tip 30 into its mounting chamber 28 is limited by the high end of the cut 70, thereby eliminating need of any shoulder or other means to limit insertion of the pen tip into its mounting chamber.

If desired, a pen tip mounting bushing 72 may be provided to prevent crushing of the delicate internal microcapillary passageways of the fiber pen tip 30 during insertion. Full details of bushing 72 are set forth in greater detail in my above mentioned copending application Ser. No. 222,047. Although cut 68 has been set forth as a flat planar cut, obviously any inexpensive external angled cut may be used to assure the formation of a secondary ink reservoir within the pen tip mounting chamber 28.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is;

1. An inking pen for use with recording apparatus and having a pen head assembly comprising a pen tip mounting chamber, a pen tip inserted through the bottom of and into said chamber, means defining an ink inlet in said chamber arranged for fluid communication with an ink supply, and means defining a secondary ink reservoir within said chamber comprising: a substantial portion of the interior surface of said mounting chamber; and means defining an external angular cut in the upper end of said pen tip, the surface of said cut being angled with respect to and intersecting the long axis of said mounting chamber with a portion of said out upper pen tip end abutting the upper interior of said pen tip mounting chamber, offset from said ink inlet and a portion of said cut upper pen tip end abutting the interior of said chamber substantially mesially thereof to form, in conjunction with said mounting chamber interior surface substantial portion, said secondary ink reservoir, whereby the upper terminal portion of said angularly cut pen tip end abutting the upper end of the chamber assures the integrity of said secondary ink reservoir upon insertion of said pen tip thereinto.

2. An inking pen as recited in claim 1, wherein said ink inlet is disposed at the top of said pen tip mounting chamber. Y

3. An inking pen as recited in claim 1, wherein said pen tip mounting chamber comprises an internally cylindrical shell having an upper frusto-conical end tapering upwardly inwardly from said shell to said ink inlet.

4. An inking pen as recited in claim 1, wherein said pen tip comprises a fiber pen tip having inherent extremely fine diameter capillary passageways formed therein for passage of ink completely therethrough.

5. An inking pen as defined in claim 4, wherein said fiber pen tip comprises a bundle of stranded synthetic material.

6. An inking pen as defined in claim 5,wherein said synthetic material is nylon.

7. An inking pen as defined in claim 4, wherein said fiber pen tip comprises a bundle of bamboo strands. 

1. An inking pen for use with recording apparatus and having a pen head assembly comprising a pen tip mounting chamber, a pen tip inserted through the bottom of and into said chamber, means defining an ink inlet in said chamber arranged for fluid communication with an ink supply, and means defining a secondary ink reservoir within said chamber comprising: a substantial portion of the interior surface of said mounting chamber; and means defining an external angular cut in the upper end of said pen tip, the surface of said cut being angled with respect to and intersecting the long axis of said mounting chamber with a portion of said cut upper pen tip end abutting the upper interior of said pen tip mounting chamber, offset from said ink inlet and a portion of said cut upper pen tip end abutting the interior of said chamber substantially mesially thereof to form, in conjunction with said mounting chamber interior surface substantial portion, said secondary ink reservoir, whereby the upper terminal portion of said angularly cut pen tip end abutting the upper end of the chamber assures the integrity of said secondary ink reservoir upon insertion of said pen tip thereinto.
 2. An inking pen as recited in claim 1, wherein said ink inlet is disposed at the top of said pen tip mounting chamber.
 3. An inking pen as recited in claim 1, wherein said pen tip mounting chamber comprises an internally cylindrical shell having an upper frusto-conical end tapering upwardly inwardly from said shell to said ink inlet.
 4. An inking pen as recited in claim 1, wherein said pen tip comprises a fiber pen tip having inherent extremely fine diameter capillary passageways formed therein for passage of ink completely therethrough.
 5. An inking pen as defined in claim 4, wherein said fiber pen tip comprises a bundle of stranded synthetic material.
 6. An inking pen as defined in claim 5, wherein said synthetic material is nylon.
 7. An inking pen as defined in claim 4, wherein said fiber pen tip comprises a bundle of bamboo strands. 